Urticaria is a skin condition characterized by the appearance of raised, red, itchy welts. These lesions can vary in size and form clusters that appear on various areas of the body, such as the face, arms, legs, and trunk. Although the welts usually disappear on their own after a few hours or days, in some cases they can recur, significantly affecting the well-being and quality of life of those who suffer from it.

Urticaria is a common and often disconcerting skin reaction that manifests as the appearance of welts or bumps on the skin. These lesions, which can range in size from small spots to large plaques, are characterized by being raised, red, or skin-colored, and typically intensely itchy. Although it can be alarming, in most cases, urticaria is a benign and transient condition.

Urticaria occurs when certain cells in the body, called mast cells, release histamine and other chemical mediators into the bloodstream. This release causes the small blood vessels in the skin (capillaries) to leak fluid, resulting in the formation of the characteristic edematous (swollen) welts.

The main symptoms of urticaria include:

Hives: Raised, well-circumscribed lesions that may be pale in the center and red at the edge.

Pruritus: Itching that can range from mild to very intense.

Evanescent Character: One of the most distinctive characteristics is that individual welts usually disappear in less than 24 hours without leaving a mark, although new ones may appear on other areas of the body.

In some cases, urticaria may be accompanied by angioedema, a swelling of the deeper layers of the skin. Angioedema commonly affects the eyelids, lips, hands, feet, or genitals and can cause a feeling of tightness or pain. If angioedema affects the throat or tongue, it can make breathing difficult and is considered a medical emergency.